Indazolium derivatives



United States Patent 3 Claims. as. zen-sis The present invention concerns new indazolium derivatives and dyestufis produced therefrom.

French patent of Addition 1,211,449 of May 6, 1960 describes dyestufis with the general formula:

Alkyl-N CH fo Alkyl (I) in which Z represents the residue of a diazotisable primary aromatic or heterocyclic amine, free from solubilising groups, such as hydroxy, sulphonic or carboxy groups but possibly substituted by halogen atoms, nitro, alkyl, alkoxy, sulphonamido, alkylsulphonyl, acylamino, carbonamido or nitrile groups, A is a monovalent anionic radical or its equivalent, and the Alkyl groups may be identical or diflferent.

According to this patent of addition, dyestuffs with the general Formula I may be prepared in various ways:

The azo dyestuffs obtained by coupling the diazo compounds of bases having the formula ZNH with 6- aminoindazole may be'treated with an alkylating agent, for example in solution in a chlorinated benzenic hydrocarbon. Under these conditions, salts are obtained with the Formula II which avoid a greater degree of alkylation due to their insolubility in the reaction medium.

IITHz ZN=N HA N /CH N Alkyl (II) The free bases of these dyestuffs, corresponding to the bracketed portion of Formula II may be precipitated by rendering alkaline the aqueous solution of the salts of Formula II by means of a base, such as ammonia or caustic soda. When treated again in solution in an organic solvent such as, for example, chlorobenzene, the xylenes, or nitrobenzene, with an alkylating agent, they yield quaternary dyestuffs of Formula I. However, experience shows that the reaction is never complete, probably due to the steric hindrance which makes the introduction of the second alkyl group in the 1-position diificult. The dyestuffs prepared in this manner are contaminated with the starting products and their purification is diiiicult.

Another method of preparing dyestuifs of Formula I consists in coupling the diazo derivatives of bases having the formula Z-NH with a 6-amino-2-alkyl-indazole and in quaternising the resulting dyestufi's. However, the 6- amino-Z-alkyl-indazoles are not easily accessible andthe second phase of the method presents the same difiiculties as the preceding method.

A third method for preparing dyestuffs of Formula I consists in treating with an alkylating agent the isomers (III) of dyestuffs of Formula II obtained by coupling 3,l%,2 Patented Mar, 30, 1%65 the diazo derivatives of bases having the formula Z-NH with 6-amino-l-alkyl-indazoles. Generally, this method yields, after complete reaction, pure dyestuffs and the 2 position is sterically unobstructed.

Unfortunately, the G-amino-l-alkyl-indazoles are available only in poor yields after a very difficult separation of their 2-alkyl isomers so that the third method of preparation is technically no more profitable than the two preceding ones.

We have now found that dyestuits of Formula I are (III) generally very easily accessible with excellent yields and.

with a high degree of purity by a fourth method, using 1,2- dialkyl-6-amino-indazolium salts.

These salts are new products and they may be obtained, for example, in the following manner:

6-nitro-indazole is treated with an alkylating agent, possibly in solution in an organic solvent such as benzene or its chloro derivatives, toluene, or the xylenes. Amongst thealkylating agents that may be used are, for example, halides, arylsulphonates, or alkyl sulphates.

One obtains a 1,2-dialkyl-o-nitro-indazolium salt which Moreover, in the first phase of this reaction, the 6- nitro-indazole may be replaced at choice by one of its l-alkyl or 2-alkyl derivatives, according to whether the allcyl group of the alkylating agent is the same or different from that already fixed in the 1 or 2 positions, resulting in compounds (IV) or (V) having identical or different alkyl groups.

The l,Z-dialkyl-S-amino-indazolium salts are crystalline colourless compounds which are generally very soluble in water. The aqueous solutions are stable, especially at a pH lower than, or equal to, 7, and have the property of coupling easily within this pH range with the diazo derivatives of primary aromatic or heterocyclic amines.

This property, which is rather surprising in view of the strongly electro-attractive nature of the quaternary ammonium group, makes it easy to arrive at dyestuffs with the Formula I. t

solute alcohol.

a, naoao The present invention relates therefore to a method for preparing dyestuils having the general Formula I, which comprises coupling the diazo derivative of an amine having the formula Z-NH with an indazolium salt having the general Formula V.

The nucleus Z of Formula I may have other substituents than those mentioned in the French patent of addition, such as, for example, the trifluoromethyl, alkoxycarbonyl, fluorosulphonyl, phenoxy or phenoxysulphonyl group, and the benzene nucleus of these may itself be substituted by halogen atoms or by alkyl groups.

The dyestuffs obtained in this way are of great interest for dyeing fibres based on the polymers or copolymers of acrylonitrile, owing to their strong afiinity for these fibres. The resulting shades, covering especially the range from yellow-to-red, are usually characterised by their very good general fastness.

The invention will be more clearly understood by reference to the following examples, which are purely illustrative and in which parts are by weight unless otherwisestated.

EXAMPLE 1 82 parts of 6-nitro indazole are introduced in fractions over 30 minutes into 126 parts of freshly distilled dirnethyl sulphate. The mixture is heated'for two hours to 135 140 C. and then allowed to cool to 80-90 C., diluted with 600 parts water and the resulting hot solution is filtered. 200 parts fine salt are added to the filtered solution and the mixture is allowed to stand for 24 hours. The crystalline 1,2-dimethyl-6-nitro-indazolium hydrochloride is filtered, centrifuged and dried. The recovered weight is 120 parts.

100 parts of this salt are redissolved in 500 parts of hot water and the resulting solution is introduced at about 95 C. over 30 minutes into a well-stirred mixture of 75 parts of fine iron filings, 300 parts of water and 7.5 parts of acetic acid, which has been brought to the boil. Heating to 95100 C. is continued for another hour, then the mixture is cooled, made slightly alkaline by adding solid sodium carbonate in order to precipitate the iron hydroxide, filtered, the iron sludge is washed with hot water and the filtrate is made slightly acid (about pH 6) by adding acetic acid. The solution of 6amino-1,2-dimethyl-indazolium salt may be used directly for the preparation of azo derivatives after determination, for example by means of a titrated solution of the azo compound of m-nitraniline. It is stable without appreciable alteration for several days. Moreover, the salt may be isolated by concentrating the reduction solution to a small volume. The white crystalline product may be purified by recrystallisation from ab- Melting point (not corrected): 227- 228 C.

EXAMPLE 2 12.7 parts of o-chloroaniline are dissolved in 150 parts of water and 30 parts by volume of concentrated hydrochloric acid, cooled to C. by adding ice and diazotised by pouring a solution of 6.9 parts of sodium nitrite into 25 parts water. After about 20 minutes, the slight excess of nitrous acid is destroyed by adding just the right amount of sulphamic acid, and the diazo solution is poured into a solution of 22 parts of l,2-dimethyl-G-amino-indazolium hydrochloride in 200 parts of water and 28 parts of crystalline sodium acetate. The coupling is very rapid and the major part of the dyestuff is precipitated. When the entire diazo derivative has disappeared, the dyestuif is precipitated by adding 40 parts of sodium chloride. After several minutes agitation, the mixture is filtered, centrifuged and dried at 60-70 C.

Weight recovered: 35 parts of a dyestulf colouring fibres based on acrylonitrile polymers to a vivid yellow shade and having good general fastness.

The crude dye melts at 255-256 C. After recrystallisation from alcohol the melting point (uncorrected) is 259-260 C. Without lowering by mixing with the dyestuir obtained according to Example 2 of the patent of Addition 1,211,449,.

13.8 parts of finely divided o-nitraniline, 6.9 parts of sodium nitrite and 25 parts of water are made into a paste and this paste is placed into a mixture of 30 parts by volume of concentrated hydrochloric acid and parts of water at 1215 C. The mixture is stirred for 20 minutes, the excess of nitrite, if present, is destroyed, the product filtered, and the diazo derivative poured into a solution of 22 parts of 1,2-dimethyl-6-amino-indazolium hydrochloride in 200 parts water. No addition of sodium acetate is necessary and the coupling is very quickly terminated. The precipitation is activated by salting with 50 The product is filtered, centrifuged and dried at 70 C., with a yield of 31 parts. It represents a new dyestufi" which dyes fibres based on acrylonitrile polymers and copolymers to a full-bodied orange shade with excellent fastness, especially to light.

parts of sodium chloride.

15 parts of 2-amino-benzothiazole are dissolved in 200 parts of acetic acid. 20 .parts of 66 B sulphuric acid and 100 parts of water are added. The mixture is cooled to 0 C. and diazotised' by adding a solution of 7 par-ts of sodium nitrite in 50 parts of 66 B sulphuric acid. After 30 minutes, this solution is poured into a solution of 22 parts of 1,2-dimethyl-6-amino-indazole hydrochloride in 600 parts of Water. the diazo derivative has disappeared, the precipitated dyestuff is filtered and washed in salted Water (2 /2 in EXAMPLE 3 EXAMPLE 4 order to eliminate the excess acid.

The new dyestui'f, dried at 60-70 C., weighs about 22 parts. It dyes fibres based on acrylonitrile polymers and Coupling is rapid. When copolymers to a bright, full bodied orange.

Other new dyestufis according to the invention, which may be prepared in a similar manner to the above examples are given in the following table:

first French Table I No. Diazotised base Z--NH: Shade on polyaerylic fibres 5 m-Chloroaniline- Yellow. 6 p-Ohloraniline.-- Do. 7 2,5-dichloro-aniline Golden yellow. 8 m-Toluidine Yellow. 9 p-Toluidine Do. Do. Yellowish orange. Golden yellow. Reddish orange. Orange.

Yellow. 2-methyl-4-nitro-aniline Orange. 2-ehloro-4-nitroaniline Yellowish orange.

18 4-chloro-2rnitro-aniline- Orange yellow. 19--- 4-llqenzoylamino-5-methoxy-2-ohloro-aniellow.

me. 20---" 2-methoxy-fi-diethylsulphonamido-aniline. Do. 21--..-. 2-methoxy-5-carbonamido-aniline. Orange. 22.. 2,5dimethoxy-aniline Yellow ochre.

3-diethylsulphonamidoA-methyl-anilineII:

2-methoxy-5-methyl-aniline. 2-methoxy-5-ehloro-auiliue Bistre yellow.

Golden yellow.

Z-nitroA-methyl-aniline Orange. 3-nitro-4-methyl-6-methoxy-amlme Golden yellow. 2-methyl-4-chloro-aniline- Do. 2-methyl-5-ehloro-aniline Do. 3,4dichloro-aniline Yellow. 3-nitro-4-ehloro-anilin Golden yellow. 4-cyan0-aniline D0. 3-eyanoA-methyl-anillne- D0. 3-sulphonamido-aniline- Yellow. 4-sulphonamido-aniline Golden yellow. 2-n1ethoxy-5-sulphonamido-aniline Do.

2-methyl-5-diethylsulphonamido-anili 4-phenylsulphonamido-aniline 3-phenylsulph0narnido-4-methyl-aniline. 4-is0propylsulphonamldo-aJ1ilino 4-diethylsulphonamido-aniline 4-die thylaminopropylenesulphonamidoamlm 2-methy1 4-dimethylsulphonamido-aniline. 2-methylsulphonyl-aniline 4-methylsulphonyl-aniline 2-methyl-5-methylsulphonyl-anillne 3-trifluoromethyl-aniline Do. Greenish yellow.

Do. Do. Yellow. Do. Do.

. Do. Golden yellow.

Do. a

Do. Greenish yellow.

Table 1Continued Table II No. Diazotised base Z NH2 Shadepn poly- N o. Diazotised base ZNH Shade on polyacryllc fibres acrylic fibres 2-methoxycarbonyl-aniline Golden yellow. 82 p-Nitraniline Orange. 4-methoxycarbonyl-nniline-- Do. 83 Z-methoxyA-nitronniline Reddish orange. 4-fluorosulpl1onyl-ani1ine Do. 84"-" 2-methyl-4-nitro-nniline Orange. 4-phenoxysulphonyl-aniline- Do. 85--. 3-chloro-aniline Yellow. 2-methy1-5-phenoxysulphonyl-an e Do. 86.-- 2-methyl-5chloro-aniline- Do. 2-chloro-5-phenoxysul honyl-aniline Do. 87-.. 2-methyl-4-oh1oroeniline- Golden yellow. 4(2 methyl-phenoxy -su lphnyl-anilin D0. 1O 88 4-phenoxysulphonyl-aniline. Do. 4-(3-rnethyl-phenoxy)-sulphonyl-anilh1e Do. 89 4-methoxycarbonyl-aniline Do. 4-(4-methyl-phenoxy)-sulpl1onyl-aniline Do. 4-(2'-ch1oro-phenoxy)-sulphonyl-aniline Do. 4-(4-chloro-pl1en0xy)-sulphonyl-aniline Do. W l i 2-methyl-4-phenylsulphonyhmiline Do. 2-phenoxy-aniline Greenish yellow. 1. A colorless compound of the formula 2-(2-methyl-phenox Do. 4-phenoxy-aniline- Do. CH 4-(2-methyl-phenoxy)-a Do. 4-(3-methyl-phenoxy)aniline Do. 93 4-(4-methyl-phenoxy)-aniline Do. 9 4-(2-chloro-phenoxy)-aniline Do. ,N A 4- (4'-chloro-phencxy)aniline. Do. 2-acetyl-4-nitro-aniline Orange. N 4-amino-2-nitro-diphenyl sulphide. Golden yellow. l-am inol nitro-diphenyl sulphide. Do. R Q2338:figgjglgfififiggfiggi'"g5;- wherein R and R are lower alkyl and A is an anionic P radical.

2. 1,Z-dimethyl-o-amino-indazolium chloride. Z-mgigo-W-nitro-d-ehloro-diphenyl sul- D a 3. 1,2-diethyl-6-amino-indazolium chloride.

p e 0. 5 a1 ha-na hthylamine Orange. bia-na fita lamine- Y Do. References Cited by the Examiner G-arm'no-in azole e ow. 4-chloro-6-amimgind1azole grzliiige yellow. UNITED STATES PATENTS 3-amin0-1,2,4i.n azo ee ow. 3-anainoindazole Do. 2,788,345 4/57 Hanhart 260-157 fi-mtm-z-ammo-thmole 2,817,658 12/57 Bossard et al. 260-457 2,971,006 2/61 Mayhew et al. 260-3096 If, in Example 1, the dimethyl sulphate is replaced by 3,037,029 5/62 Huber et a1. 260309.6

OTHER REFERENCES Auwers et aL: Berichte (D.C.G.), vol. 58, pp. 1360-69 (1925).

Davies: Jour. Chem. Soc. (London), 1955, pp. 2412 WALTER A. MODANCE, Primary Examiner.

CHARLES B. PARKER, NICHOLAS S. RIZZO,

Examiners. 

1. A COLORLESS COMPOUND OF THE FORMULA 